Re: [PATCH v5 2/3] tty: serial: qcom_geni_serial: Wakeup over UART RX

[Stephen Boyd <swboyd@chromium.org>]

Quoting Akash Asthana (2019-11-13 02:48:56)
> Add system wakeup capability over UART RX line for wakeup capable UART.
> When system is suspended, RX line act as an interrupt to wakeup system
> for any communication requests from peer.

How does the RX line get remuxed as a GPIO interrupt here? Is that
through some pinctrl magic in DT or just via enabling/disabling the
interrupt?

> 
> diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
> index 634054a..56dad67 100644
> --- a/drivers/tty/serial/qcom_geni_serial.c
> +++ b/drivers/tty/serial/qcom_geni_serial.c
> @@ -1321,6 +1327,23 @@ static int qcom_geni_serial_probe(struct platform_device *pdev)
>                 return ret;
>         }
>  
> +       if (port->wakeup_irq > 0) {
> +               /*
> +                * Set pm_runtime status as ACTIVE so that wakeup_irq gets
> +                * enabled/disabled from dev_pm_arm_wake_irq  during  system
> +                * suspend/resume respectively.
> +                */
> +               pm_runtime_set_active(&pdev->dev);

We can always set this device as active regardless of wakeup interrupt,
right? Can we move this call outside of this if?

> +               device_init_wakeup(&pdev->dev, true);
> +               ret = dev_pm_set_dedicated_wake_irq(&pdev->dev,
> +                                               port->wakeup_irq);
> +               if (ret) {
> +                       device_init_wakeup(&pdev->dev, false);
> +                       uart_remove_one_port(drv, uport);
> +                       return ret;
> +               }
> +       }
> +
>         return ret;
>  }
>